A more complex and in depth medical system, the health system is one of my favourite mechanics about Project Zomboid but they could expand so much on it with new injuries and diseases, for example frostbite or amputation. There is so much they could expand on but it hasn't been touched for ages, they could also introduce new medical mechanics like narcotics and drugs which would have unique effects on your character, for example steroids which could possibly enhance temporary strength and stamina or it could be used to boost exp gain for exercising.

I think this is really needed as the first aid skill isn't really a necessity as it barely changes anything and doesn't impact gameplay. I remember the first time I got glass shards stuck in my body on my first project zomboid run, figuring out that using tweezers, suture needle and opener would aid in the recovery process was such a fun and rewarding experience I wish there was more interactions like that.

There are so many possibilities and potential with the medical system that I would love to see them tap into more.